. >> reporter: until they followed the brown pelicans to mexico's sea of cortez. for every minute of the show, airing on discovery saturday night, there are ten hours of film that didn't make air. >> i think anything that can fly that is mechanical, manmade, put a camera on it. but we also made miniature cameras birds could carry. >> reporter: four years in the making, they hand raised snow geese and a vulture to fly with cameras for this film. >> how did they keep it on? how did you get them to keep it on? >> we basically developed harnesses and the way it was so carefully positioned, it didn't disturb their flight. >> reporter: he also used spy cameras. hidden in mud or behind faux flamingos. it took more than 100 days of shooting to get this spectacular scene. using human ingenuity to give this long dreamt-of perspective in all its wonder. anne thompson, nbc news, new york. >> spectacular. that's our broadcast on a thursday night. thank you for being here with us and please don't forget "rock center" tonight at 10:00 eastern, 9:00 central. it includes matt laue